Luc Coene, a Governing Council member at the ECB, said that even if Greece was to leave the euro, Europe would unite to protect the system.

"If the Greeks decide to leave, something that seems to me to be completely inconceivable ... Europe will certainly stand shoulder to shoulder to protect the system," he told the newspaper La Libre Belgique.

Mr Coene said that Europe was starting to take control of its budget deficits, but that it would take time to see how effective the austerity measures put in place would be.

"I think that, for the moment, we are starting to have control over the situation," he said.

"Now we need a bit of time to see what is the degree of success that all of these plans will have."

He added that investors would be cheered when they saw action to control budgets taking effect, and start to finance countries again.

"Once we see that the results are there, markets will be reassured and will finance countries," said Mr Coene, who is also the Governor of Belgium's central bank.

He dismissed the idea that the ECB should intervene by directly buying government bonds, arguing that it would not be a solution to the crisis and would require the central bank to take on a lot of political risk.

His comments came after the International Monetary Fund's chief economist said that banks exposed to Greek debt could be forced to take bigger writedowns because of the country's worse-than-expected finances.

Olivier Blanchard told CNBC television: "The [Greek] debt numbers are not good. There will have to be substantial haircuts. They have to be sufficient to allow Greece a breather."

Mr Blanchard did not give a specific figure but warned the road to Greek recovery would be a long one.

"The numbers will have to be worked out. As the macro numbers come in and they're worse, maybe the haircuts have to be larger.

"It's clear that there's going to be a long, long slog. So the Europeans will have to be ready to help with financing," he said.